Azo dye.



it. llwidae AUGUST-BLANK, 0F LE'KJTJRKUSEEI, NEAR OOLGG'NE, GERMANY, ASSIGNQR TO FARBEN- E'AZBR-IKEN VGRM. ERIE-DR. BAYER do 60., OF ELBERFELD, GERMANY, A. CORPORA- TIQN- G1" GERMANE'.

st Brewing.

- nae specification ofmetters Patent. Pa bgnted Apr, 16, 11%12, Application filed June '1, 1911, Serial No. 630,647.

To all whom it may concern: v s o 7 Be it known that 1, Answer BLANK, doctor of philosophy, chemist, citizen of the German Empire, residing at Leverkusen, near Cologne, Germany, have invenM new and useful Improvements in New Azo Dyes, of which the following is a specification.

My invention relates to the manufacture and production of new and valuable and dyestufis which are obtained by tetrazotizing one molecule of aminobenzenc-azo-l-amino- El-naphthol-sulfonic acids and by combining the tetrazo compounds with two molecules of an azo dyestufi component one of which must be resorcin. lhe new d es produce after dyeing and developing o the dye on the fiber with suitable diazo compounds, such as meta or para-nitraniline, valuable olive to brown shades, known technically as bronze and bister' brown which are very fast to Washing and to light and can be discharge to a pure white.

The new dyes are after being dried and pulverized dark powders having most probably the formula:

N=N-Y anew Naagg R meaning an aryl, X=H which may be resodium salt of 1.8-amino-naphthol-3.6-disul fonic acid containing 250 parts of sodium carbonate. When the copulation is complete the azo dye is saponified by boiling it with a caustic soda lye containing 350 parts of NaOH until the acetyl group is split ofi,

Subsequently ice and hydrochloric acid is added to obtain a solution which is acid to congo paper, 400 parts of hydrochloric acid are added and the aminoazodye is tetrazo- I tized at 0 with 138 parts of sodium nitrite.

After the diazotation is complete a solution 013220 parts of resorcin containing 500 parts of NapOO is added at 0 C. It is stirred for 4-5 hours, the dye is filtered oil and dried; It has most probably the formula:

and is a dark powdenyielding upon reduction with stannous chlorid and hydrochloric acid meta-phenylenediamin, 1.7-diainino-8- naphthol-3.6-disulfonic acid and aminoresorcin.

150 parts of cotton are dyed for 1 hour in a hot bath (1500-2000 liters) containing 10 parts of Glauber salt, 2 parts of sodium car bonate and a parts of the dye obtained from one molecule of meta-aminohenzene-aao-1.8- aminonaphthol-3.6disulfonic acid and 2 molecules of resorcin. The brown dyed cotton is then rinsed and introduced into a solution of para-nitro-diazobenzene hydrochlorid, made in the usual manner from 1-25 parts of para-nitranilin and diluted to from 2000 2500 liters of water and to which shortly before the use a"; parts of sodium carbonate have been adde After half anhours treatment the yellowishbronze dyed cotton thus obtained is washed in a clear cciltl bath, squeezed and dried.

The dyestufi', containing instead oi the 2 molecules of rcsorcin, one molecule of re sorcin and one molecule of mete phenylena diamin as end components, produces a shade of a more bluish-bronze tint, while the shades of the products, prepared from acidyl-para-phenylenediamin are more olive. Instead of para-nitranilin also other suitable diazo compounds can be'used.

, I claim LThe herein de'scr1bed new azo dyestufis which contain an amino-benzene-azo-l-ainino-8-naphthol sulfonic acid as middle component and resorcin as at least one of its end components, which dyestufis yield upon reduction with stannous chlorid and hydro chloric acid a phenylenediamin, a dieminonaphthol sulionic acid and aminoresorcin and producing after dyeing and develo ing of the dye on the fiber with suitable iazo compounds valuable olive to brown shades which are very fast to washing and to light and can be discharged to a pure white, substantially as described. v

2. The herein described new azo dyestuff having most probably the formula v gHN L H3\OI? \2825 which is after being dried and pulverized a dark powder, yielding iipon reduction with stannous chlorid and hydrochloric acid metaphenylenediamin, 1.7-diamino-8-naphthol- 316-disulfonic' acid and aminoresorcin and and can be discharged to a pure white, sub-' stantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

AUGUST BLANK. [LS-1 Witnesses:

ALBERT F. NUFER, ALFRED HENKEL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. G. 

